asin(x): Trigonometric Arcsine¶

Trigonometric arcsine function.

Declaration¶

Syntax¶

retval = asin(x)
elemental real(p) function asin(x)
elemental complex(p) function asin(x)

Arguments¶

x the input value, can be real or complex; less than or equal to 1.

Return values¶

The returned value has the kind of the input value and TYPE may be real or complex.

Description¶

asin(x) computes the arcsine of the argument x.

The arcsine is the inverse function of the sine function. It is commonly used in trigonometry to find the angle when the lengths of the hypotenuse and the opposite side of a right triangle are known.

Types¶

Supported argument types float, double, complex float, complex double.

interface asin
    module procedure sasin, dasin, casin, zasin
end interface

contains

interface
    elemental real(sp) function sasin(x)
    real(sp), intent(in) :: x
    end function

    elemental real(dp) function dasin(x)
    real(dp), intent(in) :: x
    end function

    elemental complex(sp) function casin(x)
    complex(sp), intent(in) :: x
    end function

    elemental complex(dp) function zasin(x)
    complex(dp), intent(in) :: x
    end function
end interface

Examples¶

program intrinsics_asin
    implicit none
    integer, parameter :: arg_x = kind(0.0)
    real(arg_x) :: x1
    real :: retval_x
    real :: arg_x
    retval_x = asin(0.84147098)
    print *, ret_val_x
    retval_x = asin(x1)
    print *, ret_val_x
end program

Result:

0.99999
0.99999